Endoscope technology has advanced significantly since its initial creation. Early endoscopic devices included a rigid, substantially linear shaft permanently attached to a handle, a light delivery system extending from the shaft to the handle and receiving light from an external source, and a plurality of optical lens for transmitting an image to an eyepiece. Since then, the endoscope has grown increasingly complex, incorporating a flexible shaft, a shaft with a working channel for communicating fluids or medical tools, mechanical components extending from the handle to articulate the shaft, a light source embedded within the handle, optical fiber bundles for transmitting an image from a distal end of the shaft to an eyepiece on the handle, and/or distal imagers.
However, as the endoscope becomes more complex, component failure and failure due to damage also increases, especially with regard to fragile components positioned within the shaft section of the endoscope. This is particularly true for flexible endoscopes, wherein delicate components within the flexible shaft, including the outer sheath, may be subjected to excessive bending, twisting, coiling, and fluid contamination. When one of these internal components is damaged or fails, the entire endoscopic device requires extensive repair. Both shaft and handle must be sent to a medical device manufacturer for repair. This requires a significant amount of down time (e.g., repair time, shipping time to and from the manufacturer) in which the medical practitioner/surgeon is without the endoscope. To minimize the inconvenience, the surgeon can request a loaner-endoscope from the medical device manufacturer. However, this option still involves some downtime and requires that the surgeon pay extra fees for renting the loaner-endoscope in addition to paying the costs of repairing the damaged endoscope.
In order to resolve or minimize the inconveniences associated with repairing broken endoscopes, endoscope designs have been developed in which sections of the endoscope (e.g., shaft, handle, illumination unit) can be detached by the physician. One such approach is described in U.S. Pat. No. 4,905,082 to Nishigaki et al. Nishigaki discloses a rigid endoscope comprising a rigid shaft fixedly attached to an operating section (handle), wherein the operating section has a connection ring for connecting an imaging unit thereto. The endoscope does not allow the shaft to be separated from the handle and instead provides for the imaging unit to be detachable. This design of the endoscope has significant drawbacks. The shaft is rigid and is not as maneuverable in tight areas of a body cavity as a flexible, articulating shaft. The endoscope also requires a rod lens system disposed in the shaft to transfer an optical image to the imaging unit. If there was a problem with the endoscope capturing an image, it may not be readily apparent to the surgeon whether the rod lens system in the shaft and/or the imaging unit was causing the problem. Therefore, both the shaft (with the handle) and the imaging unit would still have to be sent for diagnosis and repair. Moreover, the endoscope comprises a light guide which extends from the handle into the shaft and receives light from an external source. If the light guide is damaged, then the entire endoscope—shaft and handle—has to be sent for repair.
U.S. Pat. No. 4,911,148 to Sosnowski et al. describes an endoscope having a flexible shaft which deflects along an end segment and detaches from a handle. However, the shaft is designed such that an optical image fiber within a fiber post extends outside of the main housing of the shaft. The optical image fiber, therefore, is exposed and susceptible to damage during the process of attaching/detaching the shaft to the handle. Further, with the deflection mechanism being positioned in the shaft and a deflection control ring being mounted on the handle, an interface adapted for mechanical movement is required at the shaft-handle attachment. Dynamic seals are needed to enclose the two sections of the endoscope. However, dynamic seals have a finite lifetime and are prone to wear and leakage. Both shaft and handle lack the capability to detect any leaks and discharge any fluids that enter into their interiors. Moreover, the endoscope is configured such that an image is transferred from the optical image fiber in the shaft to an optics module and eyepiece in the handle. If a distorted image was displayed at the eyepiece, the problem could be caused by damage to either the optical image fiber or the optics module. As a result, both the shaft and the handle would still have to be sent to the manufacturer for proper diagnosis and repair.
Other efforts have been made to provide an endoscope with detachable means to release and couple a handle to a shaft. For example, U.S. Pat. No. 6,004,263 to Nakaichi et al. discloses an endoscope having a handle attached to a flexible shaft via a coupling unit. Still, the endoscope includes an optical system, where a handle-mounted eyepiece is used for viewing optical images that are gathered by an objective lens in the distal end of the shaft and transmitted through an optical fiber bundle to a lens assembly in the handle. Like the above prior art, it would not be readily apparent which optical component is the cause of the problem and therefore both the handle and the shaft must be sent for diagnosis and repair. Nakaichi also discloses the endoscope having operating wires to articulate the shaft. In order to interface the operating wires to a control unit on the handle, a mechanism separate from the coupling unit is provided. This mechanism is disposed on the outer surfaces of the shaft and handle and requires that the wires be exposed outside the shaft body. The shaft, therefore, fails to be completely sealed and cannot prevent leakage of fluid into the interior of the shaft. In addition, the shaft fails to include a device for detecting and removing fluid therein.
U.S. Patent Application Publication No. 2010/0191053 to Garcia et al. discloses an articulating endoscope comprising a detachable operator control section, which has a cable wire control system, and a plurality of flexible shaft assemblies. In one embodiment, the endoscope has a handle-mounted eyepiece attached to an optical fiber bundle in the shaft. The shaft is designed with an extreme section extending beyond and outside the shaft's main body, wherein the extreme section is inserted into a cavity in the handle. Within the extreme section are optical image fibers and pull wires. This design has significant drawbacks. The extreme section, which contains delicate components of the endoscope, is exposed and susceptible to damage during attachment/detachment of the shaft into the handle. The shaft and handle also require dynamic seals to accommodate for the interface between the pull wires in the shaft and a handle-mounted steering lever. Because of the drawbacks of dynamic seals, the interiors—and internal components—of the handle and shaft are susceptible to damage and/or contamination by fluid leaking therein.
None of the above prior art references discloses a detachable shaft flexible endoscope having a design which is not prone to damage during attachment and detachment of the shaft to and from the handle. Further, the endoscopes fail to provide sufficient sealed enclosures for the shaft and handle when detached from each other and lack any means for detecting fluid leakage. The above references also teach endoscopes with optical systems comprising multiple optical lenses disposed in both the handle and the shaft. Accordingly, delicate components are located within both sections of the endoscope, thereby requiring that the handle and shaft be sent for repair when a malfunction occurs.
It is therefore desired to provide a flexible endoscope having a design which provides easier diagnosis and repair of internal components and minimizes the inconveniences associated with repair downtime. It is also desired to provide a detachable shaft flexible endoscope having a coupling mechanism for releasably attaching a flexible shaft to a handle, wherein delicate components are housed safely within the main body of the shaft and/or handle and do not extend or protrude out. It is further desired to provide a detachable and articulating shaft endoscope, wherein the handle and shaft are both protected from fluid leakage—especially at the handle-shaft attachment—when in an attached and detached configuration.